This invention relates to improved hydrogenation and other processes using an improved catalyst system.
Many metallic catalysts, usually adsorbed on inert supports, are currently available to the chemical industry for use in a large number of chemical transformations. Included among these are various metals supported on titanates, e.g., zinc titanate. A recent development in this art involves certain compositions which comprise an active metal on a carrier, said metal being active in catalyzing a given chemical process. These particular compositions consist of hydrous alkali or alkaline earth metal titanates, zirconates, niobates, or tantalates, in which some or all or the alkali or alkaline earth metal has been replaced by an ion-exchange process with a catalytically effective quantity of active metal, such as nickel, palladium, molybdenum, and the like. (U.S. Pat. No. 4,511,455, issued to R. G. Dosch, et al). The preparation of these catalysts has been thoroughly described in the following literature articles which, along with U.S. Pat. No. 4,511,455, are incorporated by reference in this application: R. G. Dosch, "The use of Titanates in Decontamination of Defense Waste", SAND-78-0710, Sandia National Laboratories, Albuquerque, N. Mex. (Jun. 1978); R. G. Dosch, "Final Report on the Application of Titanates, Niobates, and Tantalates to Neutralized Defense Waste Decontamination--Materials Properties, Physical Forms, and Regeneration Techniques", SAND-80-1212, Sandia National Laboratories, Albuquerque, N. Mex. (Jan. 1981); H. P. Stephens et al, "Hydrous Metal Oxide Ion Exchangers for Preparation of Catalysts for Direct Coal Liquefaction", I&EC Product Research & Devel., Vol. 24, 15-19 (Mar. 1985).
With respect to supports or substrates, Dosch et al recognize, in their patent disclosure, that "if necessary, the acidity or basicity of the substrate can be modified by conventional ion exchange." (col. 2, 1. 59-61). This statement summarized at the time their view of that art, a view which did not encompass any notion of what the effect of such modifications might be, if any, on chemical processes such as hydrogenation. Moreover, applicants are not aware of any publication in the literature which connects heterogeneous catalyst acidity with hydrogenation activity.